﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace WFNetLib
{
    public class Verify
    {
#region 和校验

        static public byte GetVerify_byteSum(byte[] pBuff)
        {
            return GetVerify_byteSum(pBuff, 0, pBuff.Length);
        }
        static public byte GetVerify_byteSum(byte[] pBuff, int count)
        {
            return GetVerify_byteSum(pBuff, 0, count);
        }
        static public byte GetVerify_byteSum(byte[] pBuff, int start, int count)
        {
            byte sum = 0;
            for (int i = 0; i < count; i++)
                sum = (byte)(sum + pBuff[i + start]);
            return sum;
        }
        static public byte GetVerify_byteSum(List<byte> pBuff)
        {
            return GetVerify_byteSum(pBuff, 0, pBuff.Count);
        }
        static public byte GetVerify_byteSum(List<byte> pBuff, int count)
        {
            return GetVerify_byteSum(pBuff, 0, count);
        }
        static public byte GetVerify_byteSum(List<byte> pBuff, int start, int count)
        {
            return GetVerify_byteSum(pBuff.ToArray(),start,count);
        }
#endregion

#region 字节异或校验

        static public byte GetVerify_byteXOR(byte[] pBuff, int count)
        {
            return GetVerify_byteXOR(pBuff, 0, count);
        }
        static public byte GetVerify_byteXOR(byte[] pBuff, int start, int count)
        {
            byte ret=pBuff[start];
            for (int i = 1; i < count; i++)
            {
                ret = (byte)(ret ^ pBuff[start + i]);
            }
            return ret;
        }

#endregion

#region CRC16
        static public ushort GetVerify_CRC16(byte[] pBuff)//ANSI，可能是x16+x15+x2+1
        {
            return GetVerify_CRC16(pBuff, 0, pBuff.Length);
        }
        static public ushort GetVerify_CRC16(byte[] pBuff, int count)//ANSI，可能是x16+x15+x2+1
        {
            return GetVerify_CRC16(pBuff, 0, count);
        }
        static public ushort GetVerify_CRC16(byte[] pBuff, int start, int count)
        {
            #region 常量数组
            byte[] auchCRCHi=new byte[]{
	0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
	0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
	0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
	0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
	0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
	0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
	0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
	0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
	0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
	0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
	0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
	0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
	0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
	0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
	0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
	0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
	0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
	0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
	0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
	0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
	0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
	0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
	0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
	0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
	0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
	0x80, 0x41, 0x00, 0xC1, 0x81, 0x40};
            byte[] auchCRCLo = new byte[]{
	0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06,
	0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD,
	0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
	0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A,
	0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4,
	0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
	0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3,
	0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4,
	0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
	0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29,
	0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED,
	0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
	0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60,
	0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67,
	0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
	0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68,
	0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E,
	0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
	0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71,
	0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
	0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
	0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B,
	0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B,
	0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
	0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42,
	0x43, 0x83, 0x41, 0x81, 0x80, 0x40};
            #endregion
            Union_UInt16 ret=new Union_UInt16();
	        ret.ofs_16=0xffff;
	        byte uIndex ; /* CRC循环中的索引 */
            while (true) /* 传输消息缓冲区 */
            {
                if(count==0)
                    break;
                count--;
                uIndex = (byte)(ret.ofs_h ^ pBuff[start++]); /* 计算CRC */
                ret.ofs_h = (byte)(ret.ofs_l ^ auchCRCHi[uIndex]);
                ret.ofs_l = auchCRCLo[uIndex];
            }
            return ret.ofs_16;            
        }
        static public ushort GetVerify_CRC16_CCITT(byte[] pBuff, int count)
        {
            return GetVerify_CRC16_CCITT(pBuff, 0, count);
        }
        static public ushort GetVerify_CRC16_CCITT(byte[] pBuff, int start, int count)//x16+x12+x5+1
        {
            
            #region 常量数组
            ushort[] crc16tab=new ushort[]{
                0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
                0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
                0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
                0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
                0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
                0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
                0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
                0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
                0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
                0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
                0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
                0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
                0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
                0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
                0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
                0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
                0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
                0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
                0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
                0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
                0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
                0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
                0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
                0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
                0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
                0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
                0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
                0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
                0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
                0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
                0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
                0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
            };
            #endregion   
            ushort Result = 0xffff;
            for (int i = 0; i < count; i++)
            {
                Result = (ushort)((Result >> 8)^crc16tab[(Result ^ pBuff[start+i]) & 0xff]  );
            }
            Result = (ushort)(~Result);
            return Result;  
        }
#endregion

#region IP/ICMP/IGMP/TCP/UDP等协议的校验
        static public ushort GetVerify_IP(byte[] pBuff)
        {
            return GetVerify_IP(pBuff, 0, pBuff.Length);
        }
        static public ushort GetVerify_IP(byte[] pBuff, int count)
        {
            return GetVerify_IP(pBuff, 0, count);
        }
        static public ushort GetVerify_IP(byte[] pBuff, int start, int count)
        {
            uint cksum=0;
            if (count % 2 != 0)
            {
                cksum += BytesOP.MakeShort(pBuff[count - 1],0);
            }
            for (int i = 0; i < count-1; i = i + 2)
            {
                ushort x = BytesOP.MakeShort(pBuff[i],pBuff[i+1]);
                cksum += x;
            }
            cksum = (cksum >> 16) + (cksum & 0xffff);
            return (ushort)(~cksum);
        }
#endregion
    }
}
